Method for increasing the cutting hardness of a molded body

ABSTRACT

An increase in the cutting hardness of a shaped body comprising a crystalline aluminosilicate is achieved by treating the shaped body with a gas comprising water vapor at from 100 to 600° C. and an absolute pressure of from 0.1 to 10 bar for a period of at least 20 hours, and this shaped body having an increased cutting hardness can be used in processes for chemical synthesis, in particular in a process for preparing triethylenediamine (TEDA) by reaction of ethylenediamine (EDA) and/or piperazine (PIP).

Method of increasing the cutting hardness of a shaped body comprising acrystalline aluminosilicate and use of this shaped body having anincreased cutting hardness in processes for chemical synthesis, inparticular in a process for preparing triethylenediamine (TEDA) byreaction of ethylenediamine (EDA) and/or piperazine (PIP).

The present invention relates to a method of increasing the cuttinghardness of a shaped body comprising a crystalline aluminosilicate andprocesses for chemical synthesis in the presence of a crystallinealuminosilicate catalyst, in particular a process for preparingtriethylenediamine (TEDA) by reaction of ethylenediamine (EDA) and/orpiperazine (PIP).

Chemical and physical properties of crystalline aluminosilicates(zeolites) are, for example, described in general terms in Ullmann'sEncyclopedia of Industrial Chemistry, 6th edition, 2000 ElectronicRelease, chapter 3.2 (also in ref. [46] cited there). In chapter 8.3.2.,the possibility of reducing the aluminum content of aluminosilicates by“steaming” at about 600° C. is mentioned; cf. chapter 7.6.

The dealumination of aluminosilicates by “steaming” is also known fromUllmann's Encyclopedia of Industrial Chemistry, 6th edition, 2000Electronic Release, chapter 6.3.2, and J. Weitkamp et al. (Eds.),Catalysis and Zeolites, Fundamentals and Applications, chapter 3.3.3.3(pp. 142-144), Springer Verlag, and Studies in Surface Science andCatalysis, vol. 51, “New solid acids and bases”, page 152, Elsevier1989.

It is known from G. W. Huber et al., Studies in Surface Science andCatalysis, vol.139 (2001), pages 423-430, (table 4, page 427), that theBET surface area of microporous silica (SiO₂) decreases significantlyafter treatment with water vapor and the average pore diameterincreases.

EP-A1-130 407 (Nitto) relates to a process for preparing dimethylamine(DMA) from ammonia and methanol using particular zeolite catalystsselected from among mordenite, cliroptilolite and erionite which havebeen previously brought into contact with water vapor at from 250 to700° C., preferably for a time of from 10 to 30 hours. In this process,the catalyst activity and selectivity of the reaction to DMA and tomonomethylamine and trimethylamine is increased.

EP-A1-1 192 993 (Tosoh Corp.) relates to a process for producing shapedcatalyst bodies by mixing particular amounts of amorphous silica havinga mean particle size of from 6 to 60 nm with a crystallinealuminosilicate having an SiO₂/Al₂O₃ molar ratio of at least 12, andsubsequently shaping the mixture in a “molding machine”. The shapedbodies produced in this way are said to have a hardness of at least 1kg.

JP-B-313 20 61 (Tosoh Corp.) describes the sintering of shapedaluminosilicate catalyst bodies at from 500 to 950° C. for at least onehour, e.g. 4 hours in the case of catalyst example 1, in a water vaporatmosphere for increasing the selectivity in the preparation oftriethylenediamines and piperazines.

Triethylenediamine (TEDA=DABCOO=1,4-diazabicyclo[2.2.2]octane) is animportant intermediate and end product and is used, inter alia, in thepreparation of pharmaceuticals and plastics, in particular as catalystin the preparation of polyurethanes.

There are a large number of synthetic methods for preparing TEDA, whichdiffer mainly in the choice of starting materials and the catalystsused: see, for example, EP-A1 382 055, WO 01/02404, EP-A1-1 215 211 andWO 03/004499.

EP-A1-842 936 (equivalent: U.S. Pat. No. 5,741,906) (Air Products)describes the preparation of TEDA over ZSM-5 zeolites which have beenpretreated with a chelating agent. This pretreatment can be combinedwith “steaming” (page 4, 1st line).

For a further review of the prior art concerning the preparation ofTEDA, reference may be made, for example, to EP-A1-1 215 211 (BASF AG).

It is an object of the present invention to discover an improved methodof increasing the cutting hardness of a shaped body comprising acrystalline aluminosilicate for use as catalyst in knownzeolite-catalyzed reactions, in particular for use as catalyst in aprocess for preparing triethylenediamine (TEDA) by reaction ofethylenediamine (EDA) and/or piperazine (PIP), which is simple to carryout and results in an increased catalyst operating life and catalyststability compared to the prior art. At the same time, no deactivationof catalyst should occur as a result of the method and the selectivityin the relevant zeolite-catalyzed reactions, in particular theselectivity to TEDA in the abovementioned process for preparing TEDA,should not be adversely affected.

The cutting hardness of a shaped catalyst body is a measure of itsmechanical stability. For industrial applications in knownzeolite-catalyzed reactions, including the abovementioned process forpreparing TEDA, it is generally desirable for the shaped catalyst bodyto have a cutting hardness of not less than 9.8 N (corresponding to 1.0kg), preferably >10 N, in particular >20 N.

We have found that the above object is achieved by a method ofincreasing the cutting hardness of a shaped body comprising acrystalline aluminosilicate, which comprises treating the shaped bodywith a gas comprising water vapor at from 100 to 600° C. and an absolutepressure of from 0.1 to 10 bar for a period of at least 20 hours.

The method of the present invention makes it possible for the first timeto improve the mechanical properties of a shaped catalyst body, inparticular after calcination, and to increase the cutting hardnesses byat least 20%, in particular at least 50%.

The treatment of the shaped body according to the present invention ispreferably carried out for a period of at least 50 hours, particularlypreferably at least 100 hours.

The treatment of the shaped body according to the present invention ispreferably carried out continuously at a WHSV (weight hourly spacevelocity) of from 0.05 to 5 g, in particular from 0.1 to 1 g, of watervapor per gram of shaped body and per hour(g_(water vapor)/(g_(shaped body)·h)).

The treatment of the shaped body according to the present invention ispreferably carried out at from 200 to 450° C., in particular from 300 to400° C.

The treatment of the shaped body according to the present invention ispreferably carried out at an absolute pressure of from 0.1 to 5 bar, inparticular from 0.1 to 2 bar.

The shaped body is advantageously fixed in position (fixed bed), e.g. ina tube reactor, during the treatment with water vapor.

The crystalline aluminosilicate in the shaped body preferably has anSiO₂/Al₂O₃ molar ratio of greater than 10:1, particularly preferablygreater than 50:1, in particular greater than 100:1, especially greaterthan 200:1, very particularly preferably greater than 400:1. The upperlimit of the SiO₂/Al₂O₃ molar ratio is generally 2400:1, in particular2000:1, especially 1200:1.

The crystalline aluminosilicates can be prepared by methods known tothose skilled in the art and/or are commercially available.

As consolidating shaping processes for the crystalline aluminosilicatesto be used according to the present invention, it is in principlepossible to use all methods for achieving -appropriate shaping.Preference is given to processes in which shaping is effected byextrusion in customary extruders, for example to give extrudates havinga diameter of usually from 1 to 10 mm, in particular from 2 to 5 mm. Ifbinders and/or auxiliaries are required, extrusion is advantageouslypreceded by a mixing or kneading process. In general, extrusion isfollowed by calcination steps. The extrudates obtained are comminuted ifdesired, preferably to form granules or crushed material having aparticle diameter of from 0.5 to 5 mm, in particular from 0.5 to 2 mm.These granules or crushed material and shaped catalyst bodies producedin other ways contain virtually no fines having a particle diameter ofless than 0.5 mm.

In a preferred embodiment, the shaped body to be used according to thepresent invention contains up to 80% by weight of binder, based on thetotal mass of the catalyst. Particularly preferred binder contents arefrom 1 to 50% by weight, in particular from 3 to 35% by weight. Suitablebinders are in principle all compounds used for such purposes,preferably compounds, in particular oxides, of silicon, aluminum, boron,phosphorus and/or zirconium. A binder of particular interest is silicondioxide, which can be introduced into the shaping process as, interalia, silica sol or in the form of tetraalkoxysilanes. Further binderswhich can be used are oxides of beryllium and clays, e.g.montmorillonite, kaolinite, bentonite, halloysite, dickite, nacrite andanauxite.

Examples of auxiliaries for the consolidating shaping processes areextrusion aids; a customary extrusion aid is methylcellulose. Suchagents are generally burned out completely in a subsequent calcinationstep.

The shaped body which is treated by the method of the present inventionis particularly preferably calcined beforehand at from 100 to 600° C.,in particular from 200 to 450° C., especially from 300 to 400° C. Thecalcination time is generally at least one hour, preferably from 2 to 24hours, in particular from 2 to 10 hours. Calcination is carried out in agas atmosphere comprising, for example, nitrogen, air and/or a noblegas. In general, calcination is carried out in an oxygen-containingatmosphere having an oxygen content of from 0.1 to 90% by volume,preferably from 0.2 to 22% by volume, particularly preferably from 10 to22% by volume.

In the method of the present invention, the crystalline aluminosilicatein the shaped body is particularly preferably at least partly in the H⁺and/or NH₄ ⁺ form.

In the method of the present invention, the crystalline aluminosilicatein the shaped body is preferably of the pentasil type, i.e. it has acrystalline skeleton comprising silicon dioxide and aluminum oxide.

The crystalline aluminosilicate, preferably of the pentasil type, is notsubject to any additional restrictions in respect of the material or inrespect of the process by which it can be obtained.

Examples of crystalline aluminosilicates of the pentasil type which canbe treated by the method of the present invention include the followingtypes: ZSM-5 (as disclosed, for example, in U.S. Pat. No. 3,702,886),ZSM-11 (as disclosed, for example, in U.S. Pat. No. 3,709,979), ZSM-23,ZSM-53, NU-87, ZSM-35, ZSM-48 and mixed structures of at least two ofthe abovementioned zeolites, in particular ZSM-5 and ZSM-11, and alsomixed structures thereof.

In the method of the present invention, the shaped body is preferablytreated with a gas comprising from 2 to 98% by weight, in particularfrom 30 to 90% by weight, of water vapor or consisting of water vapor.In a further embodiment, the gas comprises water vapor in theabovementioned amounts and from 2 to 80% by weight, in particular from10 to 50% by weight, of EDA.

The present invention further relates to processes for chemicalsynthesis in the presence of a crystalline aluminosilicate catalyst, inwhich a shaped body whose cutting hardness has been increased beforehandusing the method of the present invention is used as catalyst.

The syntheses are, in particular, alkylations (e.g. of aromatics bymeans of alkenes), disproportionations (e.g. of alkylbenzenes),acylations, isomerizations (e.g. of alkylbenzenes; e.g. the Arisprocess), oligomerizations, aminations (e.g. hydroaminations orformation of amines from alcohols and ammonia), alkoxylations,epoxidations of alkenes, cyclizations, hydroxylations, condensations,hydrations (e.g. of alkenes) or dehydrations.

Such syntheses are known to those skilled in the art from, for example,G. Perot et al., J. Molecular Catalysis, 61 (1990), pages 173-196,

K. Weissermel, H.-J. Arpe, Industrielle organische Chemie, Wiley, 5thed. 1998, (e.g. pages 365-373),

J. Weitkamp, L. Puppe, Catalysis and Zeolites, Springer Verlag, Berlin,1999, pages 438-538,

and R. Eckehart, P. Kleinschmit, Zeolites—Applications of SyntheticZeolites,

Ullmann's Encyclopedia of Industrial Chemistry, 6th edition(electronic), 2000, chapter 7.3.

In particular, we have found a process for preparing triethylenediamine(TEDA) by reaction of ethylenediamine (EDA) and/or piperazine (PIP) inthe presence of a crystalline aluminosilicate catalyst, in which ashaped body whose cutting hardness has been increased beforehand by theabovementioned method is used as catalyst.

As regards the way of carrying out the process of the invention forpreparing TEDA using the catalyst having an increased cutting hardnesswhich is produced according to the present invention, the teachings ofWO 01/02404, EP-A1-1 215 211 and WO 03/004499 are hereby expresslyincorporated by reference.

The process of the invention for preparing TEDA can be carried outbatchwise or preferably continuously.

The reaction according to the present invention can be carried out inthe liquid phase or preferably in the gas phase.

The reaction is preferably carried out in the presence of a solvent ordiluent.

Suitable solvents or diluents are, for example, acyclic or cyclic ethershaving from 2 to 12 carbon atoms, e.g. dimethyl ether, diethyl ether,di-n-propyl ether or isomers thereof, MTBE, THF, pyran, or lactones suchas gamma-butyrolactone, polyethers such as monoglyme, diglyme, etc.,aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene,pentane, cyclopentane, hexane, and petroleum ether, or mixtures thereofand, in particular, also N-methylpyrrolidone (NMP) or water or aqueousorganic solvents or diluents of the abovementioned type. Ammonia is alsosuitable as solvent or diluent. Water is particularly preferred assolvent or diluent, in particular as solvent.

When the reaction is carried out in the gas phase, further suitablediluents are inert gases such as nitrogen (e.g. beyond the saturation ofthe reactor feed) or argon. The reaction in the gas phase is preferablycarried out in the presence of ammonia.

For example, the reaction is carried out in the presence of from 2 to1200% by weight, preferably from 12 to 1200% by weight, in particularfrom 14 to 300% by weight, very particularly preferably from 23 to 300%by weight, of solvent or diluent, based on EDA used.

For example, the starting mixture used in the process or the reactorfeed (=feed stream in the case of a continuous process) comprises from 5to 80% by weight, preferably from 10 to 80% by weight, particularlypreferably from 20 to 70% by weight, very particularly preferably from20 to 65% by weight, of EDA and from 2 to 60% by weight, preferably from10 to 60% by weight, particularly preferably from 15 to 60% by weight,in particular from 20 to 50% by weight, of solvent(s) and diluent(s).

In a particular embodiment of the process of the present invention, EDAand one or more amine compounds which each bear a 2-aminoethyl group(—HN—CH₂—CH₂—) are reacted.

Such amine compounds are preferably ethanolamines (e.g. monoethanolamine(MEOA), diethanolamine (DEOA), triethanolamine (TEOA)), piperazine(PIP), diethylenetriamine (DETA), triethylenetetramine (TETA),tri(2-aminoethyl)amine, morpholine, N-(2-aminoethyl)ethanolamine (AEEA)and piperazine derivatives such as N-(2-hydroxyethyl)piperazine (HEP),N-(2-aminoethyl)piperazine (AEPIP), N,N′-bis(2-aminoethyl)piperazine,N,N′-bis(2-hydroxyethyl)piperazine andN-(2-aminoethyl)-N′-(2-hydroxyethyl)piperazine.

PIP is particularly preferred.

The total amount of these amine compounds present in the reactor feedis, in this particular embodiment, generally from 1 to 1000% by weight,preferably from 3 to 250% by weight, in particular from 7 to 250% byweight, in each case based on EDA used.

For example, the starting mixture used in the process or the reactorfeed (=feed stream in the case of a continuous process) contains a totalof from 0.5 to 50% by weight, preferably from 2 to 50% by weight, inparticular from 5 to 50% by weight, of these amine compounds.

Since the use of MEOA in the starting mixture or in the reactor feed inthis particular embodiment can lead to the formation of by-productswhich are difficult to separate off from the reactor output (=productstream in the case of a continuous process), the content of this aminecompound in the starting mixture or reactor feed is preferably from 1 to50% by weight, based on EDA used.

After the reaction, the products formed are isolated from the reactionproduct mixture by customary methods, e.g. by distillation and/orrectification; unreacted starting materials can be returned to thereaction.

Thus, PIP present in the reaction product mixture from the process ofthe present invention can be separated off from this, e.g. bydistillation, and returned to the reaction.

An advantage of the process is that intermediate fractions containingboth TEDA and piperazine which are obtained in the work-up of thereaction product mixture and fractions comprising, for example,N-(2-hydroxyethyl)piperazine (HEP), N-(2-aminoethyl)piperazine (AEPIP),diethylenetriamine (DETA), triethylenetetramine (TETA),tri(2-aminoethyl)amine and/or N-(2-aminoethyl)ethanolamine (AEEA) can bereturned to the reaction.

Furthermore, other amine compounds formed as waste products in otheramine cyclization/condensation reactions can be used in the reaction ofthe present invention without the yields of TEDA being significantlyimpaired.

In a particularly preferred embodiment, the process of the presentinvention is carried out, in particular in the case of a continuousprocess (steady state), using a mixture of EDA and from 14 to 300% byweight of water and from 7 to 250% by weight of PIP, in each case basedon EDA,

preferably EDA and from 23 to 300% by weight of water and from 8 to 250%by weight of PIP, in each cased based on EDA,

particularly preferably EDA and from 33 to 250% by weight of water andfrom 17 to 250% by weight of PIP, in each case based on EDA,

very particularly preferably EDA and from 110 to 185% by weight of waterand from 25 to 100% by weight of PIP, in each cased based on EDA,

in the reaction.

In this embodiment, the proportion of PIP or of EDA can also be reducedor increased to an extent of from 0.01 to 20% by weight, for examplefrom 0.01 to 10% by weight, in favor of one and at the expense of theother.

For example, the starting mixture used in the process or the reactorfeed comprises, in this particularly preferred embodiment, from 10 to60% by weight of water, from 20 to 70% by weight of EDA and from 5 to50% by weight of PIP,

preferably from 15 to 60% by weight of water, from 20 to 65% by weightof EDA and from 5 to 50% by weight of PIP,

particularly preferably from 20 to 50% by weight of water, from 20 to60% by weight of EDA and from 10 to 50% by weight of PIP,

very particularly preferably from 45 to 55% by weight of water, from 30to 40% by weight of EDA and from 10 to 30% by weight of PIP,

where the proportion of PIP or of EDA can be reduced or increased to anextent as described above in favor of one at the expense of the other.

In this particularly preferred embodiment of the process, the reactorfeed preferably contains less than 10% by weight, particularlypreferably less than 5% by weight, in particular less than 2% by weight,of further components in addition to EDA, PIP and water.

In this particularly preferred embodiment, the reaction can, inparticular in the case of a continuous process (in the steady state), becarried out at the abovementioned ratios or amounts of startingmaterials in such a way that EDA is converted virtually completely (i.e.conversion greater than 95%, in particular greater than 97%) into TEDAand PIP with a selectivity greater than 90%, in particular greater than95%.

In the process, the EDA/PIP ratio in the reactor feed (=feed stream inthe case of a continuous process) is preferably set within theabovementioned ranges so that the consumption of PIP tends toward zero(e.g. from 0 to 30 kg, in particular from 0 to 15 kg, very particularlypreferably from 0 to 10 kg, per 1 00 kg of TEA in the reaction productmixture), in particular is zero, in the overall balance as a result ofPIP being separated off from the reaction product mixture and beingrecirculated to the reactor feed, and at the same time the EDA used isreacted completely (>95%, in particular >97%, very particularlypreferably >99%). This means that essentially no additional PIP issupplied to the process during continuous operation.

Since the amount of EDA discharged tends toward zero in such a mode ofoperation, the fractionation of the reactor output, e.g. by distillationand/or rectification, is particularly simple in this process variant.

The reaction temperature in the process of the present invention ispreferably from 270 to 400° C., particularly preferably from 310 to 390°C., in particular from 310 to 350° C.

The starting components or the reactor feed are advantageouslypreheated.

Furthermore, the following reaction conditions have been found to beadvantageous in carrying out the process:

-   -   a WHSV (weight hourly space velocity) based on amines used in        the reaction of from 0.05 to 6 h⁻¹, preferably from 0.1 to 1        h⁻¹, particularly preferably from 0.3 to 1 h⁻¹, and    -   a pressure (absolute) of from 0.01 to40 bar, in particular from        0.1 to 10 bar, preferably from 0.8 to 2 bar.

Suitable reactors in which the process of the present invention can becarried out are stirred vessels and in particular tube reactors andshell-and-tube reactors. The zeolite catalyst is preferably present as afixed bed in the reactor.

The reaction in the liquid phase can be carried out, for example, in thesuspension mode, the downflow mode or the upflow mode.

The preferred reaction in the gas phase can be carried out in afluidized bed of catalyst or preferably in a fixed bed of catalyst.

The way in which the process of the present invention can be carried outis additionally described by way of example in the following paragraph:

The reactor feed (composition: as described above) is brought into thegas phase in a vaporizer, which may be part of the actual reactor, at250-500° C. and passed over the catalyst. The reaction product mixtureobtained in gaseous form at the reactor outlet is quenched at 20-100°C., preferably 80° C., by means of liquefied reaction product mixturecirculated by pumping. This liquefied reaction product mixture is workedup as follows: in a first distillation stage, low boilers such asacetaldehyde, ethylamine, ammonia and water and also heterocycliccompounds which are formed as secondary components in the synthesis areseparated off. In a second distillation stage, the reaction productmixture is freed of piperazine which is recirculated to the reactorfeed. The stream of piperazine which has been separated off can containup to 20% by weight of TEDA. (As an alternative, water and piperazinecan be separated off simultaneously and be recirculated together to thereactor feed). In a third distillation stage, the desired TEDA productis isolated from the reaction product mixture by distillation and, ifnecessary, worked up further, e.g. in a subsequent crystallization stage(e.g. as described below).

EXAMPLES

The cutting hardnesses were measured on an apparatus from Zwick (model:BZ2.5/TS1S; prestressing force: 0.5 N, prestressing speed: 10 mm/min.;test speed: 1.6 mm/min.) and are the means of in each case 10 measuredcatalyst extrudates.

The detailed procedure for determining the cutting hardness was asfollows:

Extrudates were loaded by a cutter having a thickness of 0.3 mm withincreasing force until the extrudate had been cut through. The forcenecessary for this is the cutting hardness in N (newton). Thedetermination was carried out on a testing apparatus from Zwick, Ulm,having a fixed rotatable plate and a freely movable, vertical punchhaving a built-in cutter having a thickness of 0.3 mm. The movable punchwith the cutter was connected to a load cell for recording the force andduring the measurement moved toward the fixed rotatable plate on whichthe extrudate to be measured was located. The testing apparatus wascontrolled by a computer which recorded and evaluated the measuredresults. 10 straight, where possible crack-free extrudates having a meanlength of from 2 to 3 times the diameter were taken from a well-mixedcatalyst sample, their cutting hardnesses were determined andsubsequently averaged.

In the following tables of results, the weight hourly space velocity(WHSV) is reported in g of EDA+PIP (=g_(org)) per g of catalyst and perhour.

The EDA/PIP/H₂O ratio is by weight (% by weight).

The modulus is the molar SiO₂/Al₂O₃ ratio.

C=conversion in % by weight based on the amount of the material (EDA orPIP) indicated in the table used; S =selectivity of the reaction to theindicated product based on reacted —CH₂—CH₂— units from EDA and PIP.

Table 1 below shows results from experiments on the reaction of gaseousethylenediamine/piperazine/water mixtures to form triethylenediamine(TEDA). It can be seen that the “catalysts removed from the reactor” Aand B have a significantly increased cutting hardness compared to thecatalyst installed. Within the limits of measurement accuracy (±1%), theincrease in the cutting hardness is not associated with any deactivationand the selectivity to TEDA remains the same. TABLE 1 Extrudate Ø TimeHardness^([d]) C (EDA) S (TEDA) Cat.^([a]) [mm] [h] [N] [%] [%] A1.9^([b]) 0 12 95 94 410 27 94 93 B 2.1^([c]) 0 11 95 88 500 38 95 87^([a])H-ZSM-5, modulus 1000;^([b])20% by weight of SiO₂ as binder;^([c])26% by weight of SiO₂ as binder;^([d])cutting hardness.Test conditions: WHSV = 0.50 g_(org)/(g_(cat)h); T = 350° C.;EDA/PIP/H₂O = 25/25/50.

Table 2 below shows experimental results on the mechanical properties ofthe catalyst C (H-ZSM-5, modulus 1000, 20% by weight of SiO₂ as binder,extruded) after treatment with water vapor at 350° C. [WHSV =0.3g_(water vapor)/(g_(cat)h)]. There is a significant increase in thecutting hardness of the shaped catalyst bodies from 16 to 26 N after 259hours (h). After 452 h, the cutting hardness is 28 N. The performance ofthis catalyst in the synthesis of TEDA [C(EDA), C(PIP) and S(TEDA)]remains unchanged compared to the initial values within measurementaccuracy (±1 %). TABLE 2 Extrudate C S Ø Binder^([b]) TimeHardness^([c]) (EDA) (TEDA) Cat.^([a]) [mm] [% by wt.] [h] [N] [%] [%] C1.9 20 0 16 95 92 259 26 — — 452 28 95 91^([a])H-ZSM-5, modulus 1000;^([b])SiO₂;^([c])cutting hardness;test conditions: WHSV = 0.50 g_(org)/(g_(cat)h); T = 350° C.;EDA/PIP/H₂O = 25/25/50.

Table 3 below shows experimental results for the water vapor treatment[T=350° C., WHSV=0.3 g_(water vapor)/g_(cat)h] of catalyst extrudatesbased on ZrO₂ as binder material (cat. D). As can be seen, an increasein the cutting hardness from 2.6 N to 3.6 N can be achieved by means ofthe method of the present invention under the conditions described inthe case of ZrO₂ as binder material (=binder). TABLE 3 Extrudate Ø TimeHardness^([c]) Increase Cat.^([a]) Binder^([b]) [mm] [h] [N] [%] D ZrO₂1.9 0 2.6 — 72 3.0 15 262 3.6 38^([a])H-ZSM-5, modulus 1000;^([b])20% by weight of binder;^([c])cutting hardness.

The experimental results in table 4 below show that the increase in thecutting hardness achieved by means of the method of the presentinvention is not restricted to the use of H-ZSM-5 as active componentsof a shaped catalyst body. For example, a catalyst consisting of 80% byweight of H-mordenite [Si/Al ratio=7.8] and 20% by weight of SiO₂ (cat.E) displays a significant increase in the cutting hardness after (inthis case) 50 h under the treatment conditions [T=350“C and WHSV=0.3g_(water vapor)/g_(cat)h]. TABLE 4 Extrudate Ø Time Hardness^([c])Increase Cat.^([a]) Binder^([b]) [mm] [h] [N] [%] E SiO₂ 1.7 0 6.3 — 509.1 44 100 12.4 97^([a])H-mordenite, modulus 7.8;^([b])in each case 20% by weight of binder;^([c])cutting hardness

1. A method of increasing the cutting hardness of a shaped bodycomprising a crystalline aluminosilicate, wherein the shaped bodycomprises a binder selected from among oxides of silicon and/orzirconium and is treated with a gas consisting of water vapor at from100 to 600° C. and an absolute pressure of from 0.1 to 10 bar for aperiod of at least 20 hours and the shaped body has been calcined atfrom 100 to 600° C. before the treatment with water vapor.
 2. The methodaccording to claim 1, wherein the shaped body is treated for a period ofat least 50 hours.
 3. The method according to claim 1, wherein theshaped body is treated continuously at a WHSV (weight hourly spacevelocity) of from 0.05 to 5 g of water vapor per gram of shaped body andper hour (g_(water vapor)/g_(shaped body)·h)).
 4. The method accordingto claim 1, wherein the shaped body is treated continuously at a WHSV(weight hourly space velocity) of from 0.1 to 1 g of water vapor pergram of shaped body and per hour (g_(water vapor)/(g_(shaped body)·h))5. The method according to claim 1, wherein the shaped body is treatedat from 200 to 450° C. and an absolute pressure of from 0.1 to 2 bar. 6.The method according to claim 1, wherein the shaped body is fixed inposition (fixed bed) during the treatment with water vapor.
 7. Themethod according to claim 1, wherein the crystalline aluminosilicate inthe shaped body has an SiO₂/Al₂O₃ molar ratio of greater than 10:1. 8.The method according to claim 1, wherein the crystalline aluminosilicatein the shaped body has an SiO₂/Al₂O₃ molar ratio of greater than 50:1.9. The method according to claim 1, wherein the crystallinealuminosilicate in the shaped body is at least partly in the H⁺ and/orNH₄ ⁺ form.
 10. The method according to claim 1, wherein the crystallinealuminosilicate in the shaped body is of the pentasil type.
 11. Aprocess for preparing triethylenediamine (TEDA) by reaction ofethylenediamine (EDA) and/or piperazine (PIP) in the presence of acrystalline aluminosilicate catalyst, wherein a shaped body whosecutting hardness has been increased beforehand using a method accordingto claim 1 is used as catalyst.
 12. The process according to claim 11,wherein the reaction is carried out continuously and in the gas phase.13. The process according to claim 11, wherein EDA and one or more aminecompounds selected from the group consisting of monoethanolamine,diethanolamine, triethanolamine, PIP, diethylenetriamine,triethylenetetramine, tri(2-aminoethyl)amine, morpholine,N-(2-aminoethyl)ethanolamine, N-(2-hydroxyethyl)piperazine,N-(2-aminoethyl)piperazine, N,N′-bis(2-aminoethyl)piperazine,N,N′-bis(2-hydroxyethyl)piperazine andN-(2-aminoethyl)-N′-(2-hydroxyethyl)piperazine are reacted.
 14. Theprocess according to claim 11, wherein EDA and from 7 to 250% by weightof piperazine (PIP), based on EDA, are reacted.
 15. The processaccording to claim 11, wherein EDA, from 8 to 250% by weight of PIP andfrom 23 to 300% by weight of water, in each case based on EDA, arereacted.
 16. The process according to claim 11, wherein the reactiontemperature for the reaction to form TEDA is from 310 to 390° C.
 17. Theprocess according to claim 11, wherein the absolute pressure in thereaction to form TEDA is from 0.1 to 10 bar.
 18. (canceled)
 19. Aprocess for chemical synthesis carried out in the presence of acrystalline aluminosilicate catalyst, wherein a shaped body whosecutting hardness has been increased beforehand using a method accordingto claim 1 is used as catalyst.
 20. The process according to claim 19,wherein the synthesis is an alkylation, disproportionation, acylation,isomerization, oligomerization, amination, alkoxylation, epoxidation,cyclization, hydroxylation, condensation, hydration or dehydration. 21.(canceled)
 22. A shaped body prepared by the method as claimed in claim1.